Graph learning in low dimensional space for graph convolutional networks

Multimedia Tools and Applications - Graph Convolutional Networks (GCNs) recently have been adopted in several feature representation studies for different classification tasks. While many of these...     

四旋翼长续航飞行模式的设计与实现

更长的飞行时间是四旋翼无人机领域研究热点方向之一;在对实际飞行中瞬时消耗电流和电池电压数据的研究中发现,过大姿态角下电池电量消耗显著提升;为了延长飞行时间和提升电池电量使用效率,提出一种长续航飞行模式;在该模式下,基于现有的角速度串级PID姿态控制器,将飞行加速度的控制算法改为飞行速度控制,限制过大姿态角的操作;在无风、微风和强风环境下的飞行实验表明,长续航飞行模式比传统飞行方式飞行时间增加8%~20%;长续航飞行模式可广泛应用于多种无需快速变换飞行路径,但需要更长飞行时间的的应用场景中。     

广西北流铜石岭容县西山冶铜遗址初步考察

广西北流铜石岭、容县西山冶铜遗址位于北流江河畔的山坡山顶，相距约10km，是岭南地区迄今发现最早、规模最大的冶铜遗迹。考古部门曾对北流铜石岭遗址进行过部分发掘和研究，显示其冶铜年代约在汉至魏晋时期。于2006年11月对北流铜石岭、容县西山遗址的考察发现了杯纹岩刻、炼铜炉址以及大量散落炉渣、鼓风管残片、陶片遗存，其冶炼技术水平及冶炼工艺等尚待深入研究。     

微波条件下水分含量对淀粉醚化反应的影响

以木薯淀粉为原料,3-氯-2-羟丙基三甲基氯化铵为阳离子醚化剂,自制碱性复合催化剂为醚化催化剂,采用微波法制备阳离子淀粉。研究探讨不同醚化剂用量、不同微波功率、不同微波时间条件下,反应体系水分含量对阳离子醚化反应效率的影响。结果表明,不同的醚化剂用量、不同的微波功率及不同的微波时间组合,获得最佳醚化反应效率所需的反应体系水分含量各有不同。醚化剂用量较高时,选用较高的体系水分含量以及较高的微波功率和较长的微波时间,可获得较高的醚化反应效率;醚化剂用量较低时,选用中等的体系水分含量以及中等的微波功率和较长的微波时间,可获得较高的醚化反应效率。     

以网络百科为平台发展学生在物理化学课程学习中的批判性思维

文章探索了一种大学生批判性思维的培养模式。讨论了批判性思维的重要意义、介绍了利用网络百科实施课堂教学的方法和步骤、对反馈结果进行分析。实践结果表明教学效果良好。     

Explicit modified mild-slope equation for wave scattering by piecewise monotonic and piecewise smooth bathymetries

The mild-slope equation and modified mild-slope equation (MMSE) have played an important role in modeling the interaction between waves and bathymetries or structures. However, they are implicit equations whose coefficients are defined by an implicit dispersion relation. In this paper, for both two-dimensional bathymetries and three-dimensional axisymmetric bathymetries with piecewise monotonicity and piecewise second-order smoothness, we are able to transform the implicit MMSE into an explicit equation by introducing a new independent variable. Besides, an alternative form of the implicit MMSE is also transformed into an explicit equation under the same assumptions. These explicit equations make it much easier to obtain analytic solutions to the MMSE. As practical examples, two analytic solutions to the present explicit MMSE for wave reflection by a single linear slope and for wave scattering by a submerged circular truncated shoal are constructed.     

Designed metal–organic framework based on metal–organic polyhedron: Drug delivery

A new metal–organic framework having formula {[NH₂(CH₃)][Cu₆(L)₃(OAc)(H₂O)₄]·xsolvent} (H4L = 3,5-bis(isophthalic acid)-1H-1,2,4-triazole) (1) was synthesized, in which two types of polyhedral cages and one-dimensional channels coexist. The incorporation of the drug 5-fluorouracil (5-FU) into the desolvated 1 was around 24.9 wt% per gram of dehydrated 1. 5-FU is released in a controlled and progressive fashion with 98% of the drug released after 120 h at PBS. The result from this work provides a new avenue for MOF to be used as potential drug delivery.     

Improving the preconditioning of linear systems from interior point methods

This paper deals with preconditioners for solving linear systems arising from interior point methods, using iterative methods. The main focus is the development of a set of results that allows a more efficient computation of the splitting preconditioner. During the interior point methods iterations, the linear system matrix becomes ill conditioned, leading to numerical difficulties to find a solution, even with iterative methods. Therefore, the choice of an effective preconditioner is essential for the success of the approach. The paper proposes a new ordering for a splitting preconditioner, taking advantage of the sparse structure of the original matrix. A formal demonstration shows that performing this new ordering the preconditioned matrix condition number is limited; numerical experiments reinforce the theoretical results. Case studies show that the proposed idea has better sparsity features than the original version of the splitting preconditioner and that it is competitive regarding the computational time.     

一种群体智能算法——狮群算法

基于狮群中狮王、母狮及幼狮的自然分工,模拟狮王守护、母狮捕猎、幼狮跟随3种群智能行为,提出群体智能算法——狮群算法.算法中不同种类的狮子位置更新方式不同.遵循自然界生物“适者生存”的竞争法则,狮王守护领土,优先享用食物,母狮合作捕猎,幼狮分为学习捕猎、饥饿进食和成年被驱逐.狮子位置更新方式的多样化保证算法快速收敛,不易陷入局部最优.最后,将算法应用于6个标准测试函数优化问题,并对比粒子群算法、骨干粒子群算法,测试结果表明,文中算法收敛速度较快,精度较高,能较好地获得全局最优解.     

Study of H2O adsorption on sulfides surfaces and thermokinetic analysis

Adsorption of water on mineral surfaces was studied using density functional theory and microcalorimetry technique. The calculation results show that galena and molybdenite are hydrophobic, while pyrite and sphalerite is hydrophilic. Thermokinetic analysis shows that the heat of adsorption is in decreasing order of pyrite, sphalerite, galena and molybdenite, which is in good agreement with the calculation results. The adsorption kinetics parameters of hydrophobic galena and molybdenite surfaces are close, while those of hydrophilic pyrite and sphalerite surfaces are very different. The adsorption rate of water on the sphalerite surface is larger than that of water on the pyrite surface.